tunnels and underground excavations, horizontal underground passageway produced by excavation or occasionally by nature’s action in dissolving a soluble rock, such as limestone. A vertical opening is usually called a shaft. Tunnels have many uses: for mining ores, for transportation—including road vehicles, trains, subways, and canals—and for conducting water and sewage. Underground chambers, often associated with a complex of connecting tunnels and shafts, increasingly are being used for such things as underground hydroelectric-power plants, ore-processing plants, pumping stations, vehicle parking, storage of oil and water, water-treatment plants, warehouses, and light manufacturing; also command centres and other special military needs.

Great tunnels of the world

tunnel

location

length

km miles

year completed

use

notes

Seikan

Japan

53.9

33.5

1988

railway

passes under stormy Tsugaru Strait between the islands of Honshu and Hokkaido

Channel Tunnel (Eurotunnel)

England-France

50.5

31.4

1994

railway

passes under the English Channel between Folkestone, England, and Calais, France

Lötschberg base

Switzerland

34.6

21.5

2007

railway

rail link under Lötschen Pass between Bern and Valais cantons

Iwate-Ichinohe

Japan

25.8

15.7

2002

railway

carries the Tohoku high-speed line through mountains between Tokyo and northern Honshu

Lærdal

Norway

24.5

15.3

2000

highway

carries the main cross-country highway through the mountains in central Norway

Daishimizu (Great Shimizu)

Japan

22.2

13.8

1982

railway

on the Joetsu high-speed line across Honshu between Tokyo and Niigata

Simplon II

Italy-Switzerland

19.8

12.3

1922

railway

rail link under the Simplon Pass, the traditional divide between northern and southern Europe

Simplon I

Italy-Switzerland

19.8

12.3

1906

railway

rail link under the Simplon Pass, the traditional divide between northern and southern Europe

Vereina

Switzerland

19.1

11.9

1999

railway

rail link under the Flüela Pass between the upper Rhine and lower Engadin valleys

Shin-Kanmon (New Kanmon)

Japan

18.7

11.6

1975

railway

carries the Sanyo high-speed line under Kanmon Strait between the islands of Honshu and Kyushu

Great Apennine

Italy

18.5

11.5

1934

railway

rail link through mountains between Bologna and Florence

Qinling

China

18.5

11.5

2001

railway

traverses the Qin (Tsinling) Mountains, the historic barrier between northern and southern China

St. Gotthard

Switzerland

16.9

10.5

1980

highway

links Uri and Ticino cantons under the St. Gotthard Pass

Haruna

Japan

15.4

9.6

1982

railway

on the Joetsu high-speed line across Honshu between Tokyo and Niigata

Severomuiskiy

Russia

15.3

9.5

2003

railway

link on the Baikal-Amur railway in the Russian republic of Buryatia

St. Gotthard

Switzerland

15.0

9.3

1882

railway

carries the Zürich-Milan line under the St. Gotthard Pass between Uri and Ticino cantons

Mount MacDonald

British Columbia, Canada

14.6

9.1

1988

railway

carries the Canadian Pacific Railway under Rogers Pass in Glacier National Park

Dayaoshan

China

14.3

8.9

1988

railway

carries a dual-track line through the Nan Mountains, northern Guangdong province

Arlberg

Austria

14.0

8.7

1978

highway

provides a road link under the Arlberg Pass between Tirol and Vorarlberg provinces

Hokuriku

Japan

13.9

8.6

1962

railway

on the Hokuriku line along the Sea of Japan

Mount Cenis

France-Italy

13.7

8.5

1871

railway

carries the main Paris-Turin line through the Alps at the Fréjus Pass

Hex River

South Africa

13.4

8.3

1989

railway

penetrates the mountains between the Hex River valley and the Great Karoo upland

Fréjus

France-Italy

12.9

8.0

1980

highway

carries the Lyon-Turin highway through the Alps at the Fréjus Pass

Cascade

Washington, U.S.

12.5

7.8

1929

railway

penetrates the Cascade Range, linking the American Midwest and Pacific Northwest